Food habits of sika deer on the Boso Peninsula,central japan

The rumen contents of sika deer (Cervus nippon Temminck) on the Boso Peninsula, central Japan, were analyzed to identify local, sexual and age-specific differences in food habits. Graminoids and woody plants were the primary foods throughout the year. In winter, the use of evergreen broad leaves increased. The food habits of sika deer on Boso Peninsula were intermediate between those of populations inhabiting northern and southern Japan. Acorns, mainlyLithocarpus edulis Nakai, were consumed in fall and winter with a peak in October. Since the availability of acorns is not influenced by foraging in previous years, it can be regarded as a stable food supply and hence may be important for deer on the Boso Peninsula. The local difference between the Amatsukominato (AT) area, having a large plantation ofLithocarpus producing acrons, and the Kamogawa-Katsuura (KK) area, having a small plantation ofLithocarpus, was recognized; seeds and fruit were consumed more in AT than in KK in fall and winter. Males consumed more seeds and fruit than females at both sites in fall. This can be attributed to sexual differences in nutritional requirement.     

A record of acorn eating by sika deer in western Japan

The rumen contents of 14 sika deer (Cervus nippon) collected in November 1996 in Yamaguchi Prefecture, the western end of Honshu, Japan, were analyzed by the point-frame method. The contents were composed of high-quality foods like deciduous and evergreen browse and acorns. The composition, which consisted of a significant amount of acorns (27.8 ± 22.5%, mean ± SD), was in contrast to that of northern sika deer populations which exclusively eat graminoid leaves including dwarf bamboos. This is the first record of acorns being a major contributor to diet for wild sika deer. By the point-frame method, acorns were underestimated, and the weight contribution was much greater.     

Fallen leaves and unpalatable plants as alternative foods for sika deer under food limitation

Feeding behavior and rumen contents of sika deer (Cervus nippon Temminck) under food limitation were studied on Nakanoshima Island, Hokkaido. During the phase of population growth, the deer subsisted on tree bark and twigs, deciduous leaves and dwarf bamboos (Sasa spp.) in the winter. After a crash in population, the deer began feeding on the fallen leaves of deciduous trees and continued to do so throughout the year. They also ate unpalatable plants Cephalotaxus harringtonia var. nana Rehd., Senecio cannabifolius Less. and Cynanchum caudatum Maxim. as winter foods, which used to remain untouched by deer, and had accordingly expanded their distributions, following a decrease in the amount of dwarf bamboos available. These facts suggest that sika deer drastically shift their foods and exploit alternative foods under conditions of food limitation.     

Comparative rumen morphology of sympatric sika deer (Cervus nippon) and red deer (C. elaphus scoticus) in the Ahimanawa and Kaweka Ranges,central North Island,New Zealand

Eighteen sika deer (Cervus nippon) and 14 red deer (C. elaphus scoticus) were sampled from two areas where these closely related species are sympatric. Total body weight, carcass weight, age class, sex, and internal parameters (e.g. liver weight, kidney weight, rumen volume) were recorded. Samples of rumen wall mucosa taken from the dorsal rumen wall, atrium ruminis, caudoventral blindsac, and ventral rumen wall were used to compare rumen morphology between the two species (and also any area, sex, and age effects). Sika deer had significantly lower papilla densities in three of the four rumen wall sites and significantly smaller papillae than red deer in two of the four sites. Surface enlargement factors (SEFs) were calculated to provide comparisons of the effective absorptive surface within the rumens of the two species. The mean SEF for sika deer (4.76) was significantly less that for red deer (6.77), which suggests a greater degree of adaptation to digesting fibrous forage. In the central North Island, New Zealand, where the habitat has been considerably modified by introduced herbivores over the last century and food resources are depleted, such an adaptation would confer a competitive advantage on sika deer over red deer. It is postulated that this diet-related difference largely accounts for the ongoing replacement of red deer by sika deer where these two species are sympatric.     

Botanical and chemical composition of rumen contents of Sika deer on Mt Goyo,northern Japan

Botanical and chemical compositions of the rumen contents of 58 Sika deer on Mt Goyo, northern Japan, collected from summer of 1988 to spring of 1989, were analyzed.Sasa nipponica, a dwarf bamboo, was important in summer (35.0%) and winter (61.4%), but it decreased to 5.6% and was replaced by browse leaves in fall, and to 28.0% and was replaced by dead leaves, twigs and bark of woody plants in winter. Crude protein was 20–25% lower in the washed fraction than in the gross fraction. It was highest (16.2%) in summer and lowest (8.6%) in winter. High protein content in summer and fall foods was attributed to forb and browse leaves. Seasonal fluctuation in protein content in the foods of these Sika deer was greater than red deer on Rhum, Scotland and smaller than wapiti in Yellowstone National Park, Wyoming, USA. Climatically, winter severity of Mt Goyo is intermediate between the two localities, which seems to explain the seasonal fluctuation of the protein level. Crude fiber wasca 33% in the ‘washed’ fraction, and did not change seasonally.     

Altitudinal variation in the diet of sika deer on the Izu Peninsula: patterns in the transitional zone of geographic variation along the Japanese archipelago

Geographical variation in the diet of sika deer Cervus nippon Temminck, 1838 has been well characterised: northern populations are grazers, whereas southern deer are browsers. This variation largely reflects genetic-based differences in morphology. However, environmental factors would be also important. If a same genetic population live in different habitats, we can check altitudinal shifts in sika deer food consumption. We hypothesised that changes in the diet of the sika deer population on the Izu Peninsula, which is located within the transitional zone of resource (vegetation) variation and encompasses a broad altitudinal range, would mirror shifts in the composition of vegetation. Analyses of the rumen contents of the deer population indicated that dwarf bamboo accounted for 10.5, 46.2, and 74.3% of the deer diet in the low (<800 m), middle (800–1000 m), and high (>1000 m) altitudinal zones, respectively. In contrast, evergreen broad-leaved species accounted for 35.7, 23.1, and 5.9%, respectively. These results suggest that the diet of sika deer is more strongly affected by environmental factors, such as plant community composition, than by genetic factors.     

Food habits and home range use of Japanese macaques on an island inhabited by deer

Food habits and home range use of a troop of Japanese macaque Macaca fuscata Blyth on Kinkazan Island (9.6km²), northern Japan, were studied from the spring of 2000 to the winter of 2002. The home range of this troop covers the area where vegetation is modified by foraging of sika deer Cervus nippon Temminck. The core areas of the home ranges of the macaque troop corresponded closely to the distributions of the staple food plants in every season. For example, leaves of Berberis thunbergii DC. and leaves of Zelkova serrata Makino in spring, berries of Berchemia racemosa Sieb. & Zucc. in summer, nuts of Zelkova serrata and Carpinus spp. in the fall of 2000 and winter of 2001, seeds of Torreya nucifera Sieb. & Zucc. in the fall of 2001, and bark of Zanthoxylum piperitum DC. in winter of 2002. Among the staple food plants, Berberis thunbergii and Zanthoxylum piperitum are more abundant on Kinkazan Island than other macaque habitats in northern Japan because they are spiny and unpalatable to sika deer, hence survive under the heavy foraging by the deer. Further, another staple food plant, Berchemia racemosa, a liana, grows abundantly at the edges of Illicium forests. Illicium anisatur is toxic and is not consumed by sika deer. Monkeys of this troop using the unique vegetation induced by sika deer grazing, fed on several plants which are not consumed by monkeys in other areas, and the home range was heavily affected by the distributions of these plants.     

Tracing the genetic roots of the sika deer Cervus nippon naturalized in Germany and Austria

To determine the geographical origin of the sika deer (Cervus nippon) naturalized in Germany and Austria, we sequenced the mitochondrial control region for 214 individuals. Adding these sequences to previously published data from native sika deer across its natural geographic range, the total comes to 245, extending what is already known about the geographical variation in this sequence in Cervus nippon. From these sequences, a neighbour-joining tree was constructed. This tree showed that the 49 different mitochondrial (mt)DNA types are grouped into three distinct phylogenetic clusters, which correspond to different geographic areas. Similarities between sequences of the naturalized sika deer and those described from native sika deer from both southern Honshu, Kyushu with associated islands, and northern Honshu suggest that the ancestors of the sika deer populations in Germany and Austria originated from the Japanese archipelago. In contrast, there is no evidence that female sika deer of Chinese, Taiwanese or north Vietnamese origin were involved in the ancestry of the present sika population in Germany and Austria.     

Effective degradation of tannic acid by immobilized rumen microbes of a sika deer (Cervus nippon yesoensis) in winter

In winter seasons, wild sika deer (Cervus nippon yesoensis) inhabiting the Shiretoko Peninsula of Hokkaido Island, Japan, mainly graze woody materials (bark and twigs, etc.) as their feed source. Most of the tree species that they feed upon contain a high level of hydrolysable tannins within the inner bark. Tannins generally lead to low protein digestion and nutrient loss to these herbivorous mammals due to tannization of proteins. In winter months, it is speculated that wild sika deer develop a mechanism to degrade the tannins which are contained in their feed sources, but rumen fluid obtained from sika deer in winter months did not exhibit any ability to degrade tannins in liquid culture medium. However, constant degradation of hydrolysable tannin was observed when Ca-alginate gel beads were used for microbial immobilization and culturing. The gel beads that had been impregnated with 0.6×10⁴ fold-diluted rumen fluid of sika deer in winter and pre-incubated for 24 h under anaerobic conditions supplemented with a 1.5 g/L sugar were reacted with 5 g/L tannic acid solution. Under these conditions, the immobilized rumen bacteria grown in the macrogel beads effectively hydrolyzed tannic acid to release gallic acid monomers. Major bacterial colonies emerging in the Ca-alginate gel beads were identified as Streptococcus macedonicus and this bacterium (EC-D140) was regarded as the most likely candidate as the tannin-degrading bacterium.     

冬末春初圈养梅花鹿健康与腹泻个体粪便菌群的比较分析

腹泻是制约梅花鹿(Cervus nippon)养殖发展的主要因素之一，通常与肠道菌群失衡有关，而健康与腹泻梅花鹿个体菌群组成变化尚不清楚。为探究健康与腹泻梅花鹿肠道菌群差异，分析梅花鹿腹泻原因，以圈养雄性梅花鹿为实验对象，采集正常及腹泻梅花鹿粪便共18份，通过16S rRNA基因测序进行比较分析。研究结果表明，腹泻组菌群丰度及多样性较健康组均有所下降。在门至属水平，腹泻组理研菌科(Rikenellaceae)、克里斯滕森菌科(Christensenellaceae)等有益菌丰度下降，Treponema＿2菌属等促炎菌丰度上升。此外，瘤胃球菌科UCG-014菌属(Ruminococcaceae＿UCG-014)和理研菌科RC9菌属(Rikenellaceae＿RC9＿gut＿group)在健康组中显著富集；疣微菌门(Verrucomicrobia)、拟普雷沃氏菌属(Alloprevotella)、阿克曼氏菌属(Akkermansia)在腹泻组显著富集。腹泻梅花鹿与健康梅花鹿粪便菌群组成和多样性存在显著差异，疣微菌门丰度升高可能是导致梅花鹿腹泻的一个原因。     

Food habits of sika deer in the Shiranuka Hills,eastern Hokkaido: a northern example from the north–south variations in food habits in sika deer

Seasonal changes in the composition of the diet of the sika deer population in the Shiranuka Hills, eastern Hokkaido, in 1998 were determined by fecal analyses. The deer were dependent on Sasa nipponica, a dwarf bamboo, throughout the year, particularly in winter when it accounted for as much as 77.7% of the diet. It accounted for 33.1% and 45.6% in spring and summer, respectively, and this decreased to 12.2% in autumn. Besides S. nipponica, all the graminoid categories accounted for large amounts (66–96.7%), while dicotyledonous plants accounted for little (3–8%) except in autumn when they accounted for 31%. The strong dependence of the Shiranuka population on graminoids was different from other Hokkaido deer populations, for example the population from Ashoro/Onbetsu and the extremely high density population on Nakanoshima Island. In spite of these differences, food for all Hokkaido sika deer was poor in winter. Along the north–south geographical cline in the food composition of sika deer along the Japanese archipelago, the Shiranuka population was positioned as a grazer type, in contrast to the southern populations. However, it is important to note that variations are great among local populations in Hokkaido.     

Suppression of Regeneration in New Zealand Mountain Beech Forests is Dependent on Species of Introduced Deer

We compared the impacts on forest regeneration of introduced sika (Cervus nippon) and red (Cervus elaphus) deer in New Zealand. Plot data were used to compare mountain beech (Nothofagus solandri var. cliffortioides) regeneration between a region with sika deer, and four regions without sika deer. All regions surveyed had red deer present. In the region where sika deer had been present for more than a decade, there was evidence of poor mountain beech seedling regeneration. In the four regions without sika deer, there was evidence of a strong regenerative response at stands with low occupancy by trees. When compared to larger deer species, sika deer have a digestive morphology allowing greater dietary versatility, which may result in them impeding forest regeneration where red deer do not. In contrast to mountain beech, some small-leaved shrub species may have been competitively advantaged by intensive browsing from sika deer. This is contra to a current view that small-leaved shrub species with interlacing branches were able to tolerate browsing from extinct ratite birds, but not introduced deer. Sika deer have been introduced into countries where other deer species are indigenous, such as Canada, Denmark, Great Britain, Czech Republic, Ireland and the United States of America. Because of their dietary advantage, sika deer may have a greater potential to impede forest regeneration and competitively exclude larger deer species, particularly at low basal area sites where impacts on tree regeneration are likely to be greatest.     

A case study on the effects of a transmission-line corridor on Sika deer habitat use at the foothills of Mt Goyo,northern Honshu,Japan

Forage biomass and habitat use of Sika deer (Cervus nippon) at a transmission-line corridor were studied at the foothills of Mt Goyo, northern Japan. Summer forage biomass in the corridor was five times greater than in the adjacentBetula grossa forest. Among the plants that increased in the corridor,Sasa nipponica (a dwarf bamboo), an important forage plant for Sika deer, was predominant. Winter utilization ofS. nipponica by Sika deer was slightly heavier in the corridor, and estimated removal ofSasa leaves was twice as great there as in the forest. However fecal pellets were more prevalent in the adjacent forest in winter. Sika deer seemed to use the transmission-line corridor as a feeding site and the adjacent forest as cover as it reduces wind speed. A transmission-line corridor is more beneficial than a large clear-cut area because it provides more forest edges.     

Characteristics of Sasa nipponica grassland as a summer forage resource for sika deer on Mt Ohdaigahara, central Japan

Recently, the sika deer, Cervus nippon Temminck, population has increased on Mt Ohdaigahara, central Japan. The dwarf bamboo, Sasa nipponica Makino et Shibata, is a primary forage plant for sika deer in this area. To demonstrate the characteristics of S. nipponica grassland, especially as summer forage for sika deer, the habitat use intensity of sika deer was estimated by fecal densities, and biomass, growth rate, removal by deer and crude protein content were examined. Sika deer utilized the S.nipponica grassland on Mt Ohdaigahara during summer when the biomass, growth rate and crude protein content of S. nipponica were high. The recent increase in the deer population seems to be partly due to S.nipponica grassland being a favorable summer habitat.     

Age-sex differences in the diets of Sika deer on Kinkazan Island,northern Japan

Dietary differences in the ages and sexes of Sika deer (Cervus nippon) were studied on Kinkazan Island, northern Japan from October 1990 to July 1991. Larger deer consumed more graminoids than smaller deer except in spring, and less dicotyledonous leaves in all the seasons. Fecal nitrogen concentrations were lower in larger deer than in smaller deer in all the seasons. The age-sex differences in foods were smaller in summer and winter when foods were most abundant and scarce, respectively, while they were greater in spring and autumn when food availability was intermediate.     

Food habits of sika deer and nutritional value of sika deer diets in eastern Hokkaido, Japan

Rumen content analysis and field observations were used to investigate the food habits and diet quality of sika deer (Cervus nippon yesoensis Heude) from 1991 to 1993 in eastern Hokkaido, Japan. Diets varied seasonally, with deer consuming graminoids and browse in winter, forbs and agricultural crops in spring and summer and all of these plant foods in autumn. Eighty-four plant species with sika deer bite marks were identified and their use also varied seasonally. The diversity of food resources available provided both critical protein and digestible energy, allowing for physiological maintenance and seasonal growth. With these high-quality diets, deer maintained good body condition in eastern Hokkaido, where the population density was relatively low.     

Nitrogen content in feces and the diet of Sika deer on the Boso Peninsula, central Japan

Fecal and rumen nitrogen content of Sika deer (Cervus nippon Temminck 1838) on the Boso Peninsula, central Japan, were analyzed concerning their seasonal fluctuations and local differences at four areas on the Boso Peninsula. The mean fecal nitrogen was high in August and low in February in all the areas. The seasonal variation, however, was relatively small. This may be the result of the following reasons: the Boso deer feed on evergreen broad-leaves containing a high and stable nitrogen content in winter; little snow falls there; and the deer consume foods relatively low in nitrogen in summer. The fecal and rumen nitrogen content in both summer and winter depended on deer density.     

Sika deer presence affects the host–parasite interface of a Japanese land leech

Since the 1990s, increasing populations of a blood feeding land leech (Haemadipsa japonica) have become a serious issue in several Japanese prefectures, and it may be caused by the increases in sika deer (Cervus nippon) populations seen over the last quarter of the century. Therefore, this study aimed to reveal the host animal species of H. japonica using iDNA (vertebrate DNA isolated from invertebrates) and to test the hypothesis that the increasingly widespread distribution of sika deer results in increased H. japonica populations through changes to the host–parasite interface. We amplified mitochondrial DNA 16S ribosome RNA fragments from iDNA isolated from the blood clots of H. japonica collected across Japan. We identified 17 host animal species, including four orders of Mammalia (Carnivora, Artiodactyla, Rodentia, and Lagomorpha) and two orders of Amphibia (Caudata and Anura). The sika deer was the dominant host species of H. japonica. Additionally, the host animal species composition of H. japonica differed according to the presence or absence of sika deer. In the sites where sika deer were not found, Anura (frog) species were the most commonly identified hosts of H. japonica. These results suggest that the increases in H. japonica populations might have occurred via a change in host preference to sika deer. This change might be driven by the increases in sika deer populations and subsequent increase in the frequency that H. japonica uses the sika deer as easy prey, as well as by sika deer providing more reproductive energy per blood meal than blood meal from frog species. The present study suggests that a more widespread distribution of sika deer resulted in an increase in H. japonica through a change in the host–parasite interface. Therefore, management that focuses on decreasing sika deer populations would likely be an effective method for the reduction of H. japonica populations.     

The evolution of nettle resistance to heavy deer browsing

We examined whether heavy browsing by sika deer, Cervus nippon Temminck, changed morphological characteristics of a Japanese nettle, Urtica thunbergiana Sieb. et Zucc., in Nara Park, where a large population of sika deer has been maintained for more than 1,200 years. Wild nettles of Nara Park exhibited smaller leaf area, 11–223 times more stinging hairs per leaf, and 58–630-times higher stinging hair densities than those of other areas where there was no evidence of sika deer browsing. There were no significant differences in stinging hair length between the areas. Nettles from Nara Park that were cultivated from seeds in a greenhouse retained a larger number and higher density of stinging hairs. In the field, nettles of Nara Park were less frequently browsed by sika deer and showed higher survivorship than nettles that were transplanted from an unbrowsed area into Nara Park. These results indicate that: (1) the U. thunbergiana population of Nara Park has an extremely high stinging hair density compared with those of unbrowsed areas; (2) this characteristic has a genetic basis, and (3) stinging hairs serve as a defensive structure against sika deer, contributing to an increase in survivorship. Thus, we conclude that a U. thunbergiana population in Nara Park, with extremely high stinging hair densities, has evolved through natural selection due to heavy browsing by sika deer.     

A comparison of food habits of two sympatric ruminants of Mt. Yatsugatake,central Japan: sika deer and Japanese serow

Comparison of food habits of sympatric animals provides understanding of interspecific relations. Previous studies of food habits of the two ruminants of Japan, sika deer (Cervus nippon) and Japanese serows (Capricornis crispus), have shown that sika deer are variable, and they are gazers in northern Japan, but browsers in southern Japan, whereas Japanese serows are browsers. However, these studies described the food habits of each species separately, and no study has compared the food habits of these species living in sympatry. Therefore, we examined these species on Mt. Yatsugatake, central Japan, using microhistological analyses and nutritional analyses of feces. Sasa nipponica, a dwarf bamboo, predominated in the fecal composition of sika deer, whereas both S. nipponica and dicotyledonous plants were found in the feces of Japanese serows. Crude protein levels of serow feces were higher than those of deer. The particle sizes of plant fragments in serow feces were smaller than those in deer feces, suggesting that serow fed more selectively on digestible plants than deer did. These results support the suggestions of previous studies conducted in different habitats and show that sika deer are less selective grazers, and Japanese serows are more selective browsers. Thus, food differences are likely explained by the feeding ecophysiology of the animals and not habitat differences.